Produção e caracterização de carvões ativados (ca) de biomassa amilácea pirolisados em forno de microondas

Abstract

This work presents a study about the production of activated carbons (AC) of amylaceous biomass. Through the characterization of the raw material (diffraction and x-ray fluorescence, thermogravimetric analysis and scanning electron microscopy) and the AC samples produced (yield, mesoporosity, micro porosity, thermogravimetric analysis, pH, point of zero charge (PZC), and others) could be argued that starch is a viable alternative as a precursor for the production of AC, which may be interesting for producers and industry, because it would reduce production costs and allow its routine application in the polishing of domestics and industrial effluents. Considering the production of AC, the controllable variable that most affected the porosity of coal was the activation. The AC sample, obtained on the condition +++ (3 upper levels of the factorial planning: the activator concentration of 5mol/L, N2 flow of 8 L/h and pyrolysis time of 30 minutes) showed the best results of mesoporosity (48.9 mg/g) and microporosity (597.9 mg/g), which represents 78% the capacity of the commercial activated carbon used as a reference. This points not just for the potential of the precursor, but also to the efficiency of the microwave as a method of pyrolysis. That sample showed pH of 5.79 ± 0.08 and PZC at pH 5.9. The removal of phenol from aqueous solutions was higher than 99%.